For more than a century, the valve industry has been blindly following its tradition in making valves such as the butterfly valves, ball valves and plug valves, which are conceived and designed in a reasoning process that lacks cleverness and resourcefulness. The valve seat and the blocking body such as the disc in the butterfly valve, ball in the ball valve and the cylindrical plug in the plug valve, continuously rub each other during the opening and closing of those valves and, consequently accelerates the abrasion and wear of the seating surfaces in these valves. The present day valve industry is witnessing the dawning of a new era wherein daring and intelligent new concepts are being introduced into the design and manufacturing of valves. One example that stands out as such a new direction in valve technology is the invention of the "Floating Disc Valve", which is a butterfly valve with variable seating pressure that is relieved and established by the axial movement of the valve stem while the traditional rotational movement of the valve stem opens and closes the valve. Another example is the ball-plug valve that works like a ball valve while it has the structural strength of the cylindrical plug valve. The seating pressure between the valve seat and the ball-end of the ball-plug is relieved or established by a minute amount of axial movement of the valve stem while the rotational movement of the valve stem opens and closes the ball-plug valve. There is little doubt that other new valves which utilize the axial movement of the stem for relieving and establishing the seating pressure and the rotational movement for opening and closing the valve, will emerge. Therefore, there is a demand for a novel arrangement of a dual action valve handle which imposes linear and angular motion on the valve stem.
The primary object of the present invention is to provide a valve handle that imposes linear movement on the valve stem under one position of the valve handle and imposes rotational movement on the valve stem under the other position of the valve handle.
Another object of the present invention is to provide a dual action valve handle that generates linear movement on the valve stem by using a jack screw mechanism providing a powerful mechanical advantage.
A further object is to provide a dual action valve handle capable of relieving and establishing the seating pressure in the valve in an easy manner in spite of the powerful resistance against such a manipulation created by fluid pressure.
Yet another object is to provide a dual action valve handle of simple mechanical structure and fool-proof operation.
Yet a further object is to provide a dual action valve handle that is ecomonic, light-weight, compact and easy to manufacture.
These and other objects of the present invention will become evident as the description of the present invention proceeds.